Fire collar

ABSTRACT

A fire collar is adapted to inhibit flame propagation through a partition and be supported to the partition and around a pipe extending through a hole in the partition. The fire collar includes a non-combustible sleeve having a pair of opposed, open ends. The fire collar further includes a layer of expandable material carried on the inner circumferential surface of the sleeve. The layer is adapted to be constrained by the sleeve to expand radially inwardly toward the pipe to collapse the pipe in the event the temperature of the material is raised above a predetermined temperature. The layer and the collapsed pipe together form a physical barrier across the sleeve to block the hole. The fire collar further includes a removable, elastic, interference member adapted to be disposed about the outer circumference of the pipe and between the inner circumferential surface of the sleeve and the pipe to create an interference fit therebetween to retain the sleeve relative to the pipe.

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/344,099, filed Dec. 19, 2001.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates, generally, to a fire collar and,more particularly, to a fire collar that inhibits flame propagationthrough a partition.

[0004] 2. Description of the Related Art

[0005] Pipes are often used in a building for plumbing, heating, andcooling applications as well as to pass electrical, telephone, andcomputer lines therethrough. These pipes are generally plastic and oftenextend through holes in fire-rated partitions-such as walls, floors, orceilings. Pipes of this type are conventionally made of ABS or PVCplastic material and adapted for connection with other plastic pipes byuse of adhesives or the like.

[0006] ABS and PVC pipes are combustible. PVC pipes, althoughself-extinguishing, usually give off poisonous gases when subject toflame while ABS pipes are black and emit smoke upon being burned. In theevent of a fire within the building, pipes of this type may burn andthen melt and/or collapse. In that event, voids in or around the pipesmay be created and act to transmit fire and/or its by-products, such assmoke and poisonous gases, through the partitions. Common sense and manybuilding codes dictate that it is desirable for the partitions tocontain the fire and its by-products from penetration through thepartitions as long as possible.

[0007] For the above reasons, fire collars are often required in wooden,steel, and concrete structures alike to ensure that such voids areblocked in the event of a fire. This ensures that fire and itsby-products are prevented, or at least inhibited, from passing from, forinstance, one story of a structure to the immediate upper story.

[0008] Fire collars of the type known in the related art typicallyinclude a flexible metal strip that is designed to be manually wrappedaround a pipe. The opposite ends of the metal strip are designed tosubstantially meet when wrapped around the pipe and can be held togetherby any suitable fastening means known in the related art. These devicesare designed also to interface between two adjoining partitions and tobe secured to one of the partitions using screws or other suitablefasteners. The fire collar supports an expandable material, such as afire-rated wrap, about the inner circumference of the wrapped metalstrip. Typically, the fire-rated wrap is co-extensively secured to themetal strip as a separate piece. In the event of a fire, the materialexpands radially inwardly and fills the void around the pipe, whichextends through at least one of the partitions. The fire collar istypically designed to prevent the material from expanding axially.

[0009] To properly install a fire collar of the type commonly employedin the related art, a substantially round hole must be cut in thepartition to a predetermined dimension. More specifically, for the firecollar to function properly, the hole must be cut so as to create,ideally, a one-eighth to one-quarter inch diametric tolerance betweenthe fire collar and the partition. The tolerance is then caulked with afire-rated caulk to secure the fire collar to the partition.Unfortunately, it is uncommon for such tolerances to be actively held inthe field. This has been one basis cited for poor performance of thefire collars known in the related art. Poor performance or failure ofthese fire collars has led to insurance claims and litigation.

[0010] Fire collars of the type generally known in the related art alsoinclude a plurality of tabs that are formed on the metal strip. Each tabincludes an aperture extending therethrough. The tabs are disposedradially outwardly from a longitudinal edge of the fire collar. Afastener is received through the aperture in each tab to mount the metalstrip to surrounding building structure after the metal strip has beenwrapped around the pipe. In particular, a screw, for instance, isinserted through the aperture in each of the plurality of tabs andfastened to the bottom side of the partition such that the tabs and thelongitudinal edge of the fire collar are in abutting contact with thepartition. This fastening scheme is designed to prevent the fire collarfrom unwrapping from the pipe due to the force of the expanding wrap inthe collar in the event of a fire. However, this is not alwaysaccomplished in practical effect. A failure to follow the specificationsfor installing a particular fire collar may void any warranty relatingto the fire collar and/or subject a contractor who is installing it toliability.

[0011] More specifically, although the diameter of the fire collar maybe adjusted, the tabs are not always disposed about the fire collar suchthat it can be properly mounted in a secure manner to the partition.Screws, which are usually specified as the proper fastening mechanism,are often rejected in favor of nails. In fact, nails are frequently usedin the field to fasten the fire collar to the partition when the tabsare not disposed about the fire collar such that screws can properlymount it in a secure manner to the partition. In operation, as the firemelts the pipe, heat from the fire causes the wrap to expand. The firecollar prevents the wrap from expanding outwardly so that the wrapexpands only inwardly to collapse the pipe and fill the void. However,when the fire collars of the type known in the related art are notproperly mounted, the fasteners fail and are pulled-out of therespective mounting surfaces, causing the fire collars to unwrap fromaround the pipes.

[0012] Generally speaking, fire rated wrap of the type conventionallyemployed in the related art typically has a two-hour fire rating.Ideally then, fire and its by-products should not penetrate the pipe,collar, and fire rated wrap for approximately two hours. However, caulkhas a one-hour fire rating and is, therefore, the weakest link in theassembly. Thus, with conventional fire collars presently employed in therelated art, the caulk determines the duration of time that the barrieris impenetrable by fire and its by-products. Various authorities,including those in the United States, also require that the barrier becapable of withstanding the force of water from a fire hose. Otherwise,attempts using a fire hose to put out a fire can, in fact, break openthe barrier and encourage the spread of the fire and its by-productsthrough the partition. Thus, it is important that fire collars aresolidly mounted in place.

[0013] Other problems are presented during installation of the firecollars known in the related art. By way of example, nail plates aretypically required by building and safety codes at strategic areas toprotect a pipe from damage. Nail plates protect adjacent pipes fromdamage by nails used by carpenters working around the pipe. Thus, firecollars of the related art require the additional time and expenseduring installation in order to avoid the nail plates used to protectvital structure found near the fire collars.

[0014] Another common problem often arises in connection with theinstallation of plastic pipes extending through holes in woodenpartitions. More specifically, plastic pipes expand and contract. Thisexpansion and contraction creates noise when plastic pipes make contactwith wood. The fire collars of the related art do not prevent theoccurrence of such noise.

[0015] Furthermore, the fire collars of the related art are typicallyinstalled by plumbing contractors, but only after a building has beenplumbed. It is only after a building has been plumbed that the plumbingcontractors must return to each pipe passing through a partition andwrap it with a fire collar. This greatly increases the cost in time andlabor for such projects.

[0016] Thus, there remains a need in the art for a fire collar that maybe easily and quickly installed at the time the building is beingplumbed as well as a fire collar that requires fewer parts duringinstallation. In addition, there remains a need in the art for a firecollar that can withstand the force of water from a fire hose in theevent of a fire and eliminates the requirement for nail plates asprotection for the pipe. Also, there is a need in the related art for afire collar that prevents the creation of noise when a plastic pipeexpands and contracts within a hole of a wooden partition.

SUMMARY OF THE INVENTION

[0017] The present invention overcomes the disadvantages in the relatedart in a fire collar that is adapted to inhibit flame propagationthrough a partition and be supported to the partition and around a pipeextending through a hole in the partition. The fire collar includes anon-combustible sleeve having a pair of opposed, open ends. The firecollar further includes a layer of expandable material carried on theinner circumferential surface of the sleeve. The layer is adapted to beconstrained by the sleeve to expand in volume radially inwardly towardthe pipe to collapse the pipe in the event the temperature of thematerial is raised above a predetermined temperature. The layer and thecollapsed pipe together form a physical barrier across the sleeve toblock the hole. The fire collar further includes a removable, elastic,interference member adapted to be disposed about the outer circumferenceof the pipe and between the inner circumferential surface of the sleeveand the pipe to create an interference fit therebetween to retain thesleeve relative to the pipe.

[0018] One advantage of the fire collar of the present invention is thatits installation does not require the use of mechanical devices-such astabs, screws, and nails-to mount the fire collar, thereby reducing cost,labor intensity, and time of installation. Similarly, the fire collar ofthe present invention eliminates the need for nail plates as protectionfor pipes at strategic areas in a building.

[0019] Another advantage of the fire collar of the present invention isthat it does not require that a hole be cut in the partition to aspecific dimension or within unrealistically close tolerances forinstallation of the fire collar.

[0020] Another advantage of the fire collar of the present invention isthat it is easy to install, thereby eliminating or reducing the risk ofvoiding a warranty relating to the fire collar and, therefore, reducesthe liability due to failure or poor performance by a plumber.

[0021] Another advantage of the fire collar of the present invention isthat it eliminates the noise created when a plastic pipe expands andcontracts within a hole of a wooden partition.

[0022] Another advantage of the fire collar of the present invention isthat it can be installed at roughly the same time as the PVC or ABS pipeis installed, thereby eliminating the need to return after suchinstallation to install the fire collar and, thereby, reducing the timerequired to install the fire collar.

[0023] Another advantage of the fire collar of the present invention isthat it can be constructed having various lengths to accommodate pipesof various sizes and types.

[0024] Another advantage of the fire collar of the present invention isthat it is noncombustible and preferably made of steel.

[0025] Another advantage of the fire collar of the present invention isthat it cannot unwrap from a pipe and, therefore, better confines andreduces the amount required of the expanding material.

[0026] Still another advantage of the fire collar of the presentinvention is that less expanding material is necessary for the firecollar to function effectively, thereby reducing cost.

[0027] Other objects, features, and advantages of the present inventionwill be readily appreciated as the same becomes better understood afterreading the subsequent description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]FIG. 1 is an elevational side view of a fire collar of the presentinvention;

[0029]FIG. 2 is an elevational top or bottom view of a fire collar ofthe present invention;

[0030]FIG. 3 is an environmental, partial, cross-sectional view of afire collar of the present invention in its operative state mountedbetween a pipe and a partition;

[0031]FIG. 4 is an environmental, partial, cross-sectional view of afire collar of the present invention in the operative state shown inFIG. 3, but after the event of a fire;

[0032]FIG. 5 is a cross-sectional side view of a fire collar of thepresent invention in its operative state mounted around a pipe.

[0033]FIG. 6 is an enlarged, partial, cross-sectional view of the beadformed on the sleeve of the fire collar of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0034] Referring now to the figures, where like numerals are used todesignate like structure, a fire collar of the present invention isgenerally indicated at 10. The fire collar 10 is shown, per se, in FIGS.1 and 2 and in its operative mode in FIGS. 3 through 5 supported arounda PVC pipe 12. The pipe 12 defines a void or passage 14. In FIGS. 3 and4, the pipe 12 extends substantially perpendicularly to and through ahole 16 defined by an upper partition 18, such as a floor of an upperstory of a building. Similarly, the pipe 12 also extends substantiallyperpendicularly to and through a hole 20 defined by a lower partition22, such as a ceiling of an immediate lower story of the building. Asillustrated in the figures, the lower partition 22 is disposed inspaced, substantially parallel relationship with respect to the upperpartition 18. A joist 24 is disposed on opposite sides of the pipe 12and extends between and substantially perpendicularly to the partitions18, 22. As illustrated in these figures, the joists 24 extendsubstantially parallel to the pipe 12 and are adapted to support thepartitions 18, 22 in spaced relationship with respect to each other asis commonly known in the art.

[0035] In this respect, the fire collar 10 is described below and shownin the figures disposed around a single plastic pipe 12. However, itwill be apparent to those having ordinary skill in the art that it ispossible to use the fire collar 10 with a plurality of interconnectedpipes. Furthermore, the fire collar 10 may be used with pipes made ofmaterials other than plastic. The fire collar 10 finds application whenthe pipes are made of a material that melts or, otherwise, collapseswhen subject to fire. In addition, the fire collar 10 may also be usedwith cable or another elongate member having a sheath around it made ofa meltable material and that passes through a partition. Thus, from thedescription that follows, those having ordinary skill in the art willappreciate that the fire collar 10 is not limited to any particular typeof pipe or conduit that extends between partitions in a building.

[0036] In the preferred embodiment of the fire collar 10 illustrated inFIG. 1, the fire collar 10 includes a hollow, continuous body of asubstantially right-cylindrical shape, resembling a sleeve 26. Thesleeve 26 has a pair of opposed, open ends 25,27. As shown in FIGS. 3and 4, part of the sleeve 26 may extend completely through the upperpartition 18 such that part of end 27 is disposed within the spacedefined between the upper partition 18 and the lower partition 22. Inoperative mode, the sleeve 26 is disposed substantially concentricallyaround the pipe 12, such that a small gap 28 is defined between the pipe12 and the sleeve 26. The gap 28 is of sufficient volume to allow thepipe 12 to expand and contract within the hole 16. Also, the wall of thesleeve 26 has a thickness sufficient to protect the pipe 12 from damagefrom exterior the sleeve 26. The pipe extends beyond ends 25,27 of thesleeve 26 in FIGS. 3 and 4 and end 27 in FIG. 5. The sleeve 26 has asufficient length such that the upper portion of the sleeve 26,including end 27, may serve as a nail plate providing protection to thepipe 12 through the upper partition 18. Those having ordinary skill inthe art will appreciate that the sleeve 26 can be constructed to haveany suitable length, thickness, and inner diameter.

[0037] The sleeve 26 also has an annular groove or bead 30 that extendsfor a substantial portion of the general outer periphery of the sleeve26. In the preferred embodiment, the bead 30 extends completely aboutthe entire outer periphery of the sleeve 26. The bead 30 projectsradially outwardly such that the bead 30 defines a pair of sides 31,33and a space 32 therebetween, as best shown in FIG. 6. The sides 31,33may be disposed at a predetermined angle a with respect to the sleeve26. For instance, as best shown in FIG. 6, this predetermined angle αmay approximate 45°. However, those having ordinary skill in the artwill appreciate that many angles over a relatively wide range may beemployed without departing from the scope of the present invention.

[0038] The bead 30 is located longitudinally offset with respect to theaxial length of the sleeve 26 and, therefore, closer to one of the ends25,27 of the sleeve 26. Preferably, the bead 30 is disposed proximateend 25 and distal end 27. More preferably, the bead 30 is disposedapproximately three-quarters of an inch from end 25. Furthermore, in thepreferred embodiment, the bead 30 is approximately one-quarter inch deepand one inch wide. However, those having ordinary skill in the art willappreciate also that the bead 30 can have any suitable shape, depth,width, and length and be disposed in any suitable relationship with thesleeve 26.

[0039] Space 32 defined by the bead 30 is designed to be filled with anapproved fire-rated material 34. The material 34 may be of any suitabletype that, when heated to a predetermined temperature, such asapproximately 250° F., expands in volume by a factor of, for example,fifteen to twenty-five. Any suitable material may be used, and there areproprietary materials available, ranging from a graphite-based materialto other materials, that are well known to those skilled in the relatedart. However, those having ordinary skill in the art will appreciatethat the material 34 may extend over a portion or even the entire innercircumference of the sleeve 26 or any other suitable surface area andexpand to any suitable volume at any suitable temperature.

[0040] Also, the material 34 may be disposed within the bead 30 in anynumber of ways. For instance, the material 34 may be formed as acomposition strip one-quarter inch thick and one inch wide that iscemented or otherwise held in place to the inner circumference of thebead 30. However, those having ordinary skill in the art will appreciatethat the material 34 can have any suitable shape, thickness, width, andlength and be fastened to the inner circumference of the bead 30 by anysuitable means.

[0041] In the embodiment illustrated in FIGS. 3-4, the sleeve 26 isfixed within the hole 16 to the upper partition 18 by a removable,elastic, interference member 36 adapted to be disposed about the outercircumference of the pipe 12 and between the inner circumferentialsurface of the sleeve 26 and the pipe 12 to create an interference fittherebetween to retain the sleeve 26 relative to the pipe 12. Theinterference member 36 may be a washer, an O-ring, a rubber band, or anyother suitable device that may be disposed between the sleeve 26 and thepipe 12. Those having ordinary skill in the art will appreciate thatthis list of devices is for representative purposes only and not by wayof limitation.

[0042] Thus, there is no need for a plumber to cut the hole 16 to aspecific dimension for the fire collar 10 to work properly. Also, fixingthe sleeve 26 to the pipe 12 does not require the use of mechanicalfasteners, like screws and nails. And, the fire collar 10 can beinstalled at the same time the corresponding piping is installed. Thisfeature greatly reduces the time and labor costs associated withinstalling the fire collar of the present invention.

[0043]FIG. 4 illustrates the situation where the pipe 12 and the firecollar 10 have been subjected to a fire such that they have reached atemperature of approximately 250° F., for example. In this event, thematerial 34 expands inwardly, but is constrained from expanding radiallyoutwardly by the unitary, concentric steel sleeve 26. As the material 34expands inwardly, the material 34 pushes the pipe 12 radially inwardly.As the pipe 12 melts, portions of the wall of the PVC or ABS pipe 12 aredriven toward each other by the expanding material 34 and come togetherand become intimately mixed with the expanding material 34. Thus, aphysical barrier across the passage 14 defined by the pipe 12 is formedby the material 34 and melted plastic. As a result, the rising fire andits by-products are prevented from spreading and passing from the lowerpartition 22 to the upper partition 18 through and immediately aroundthe pipe 12. Also, the strength of the barrier is sufficient towithstand the force of the water from a fire hose.

[0044] There is no bleeding around the open ends 25,27 of the sleeve 26by the material 34 in the event of expansion due to fire, as in the caseof conventional fire collars. Thus, less material 34 is necessary forthe fire collar 10 to function effectively. The fire rated material 34is an expensive component of any fire collar. The efficient use of thefire rated material 34 in connection with the fire collar 10 of thepresent invention is another factor that may reduce costs relate to firecollars known in the related art.

[0045] As noted above, the sleeve 26 described and illustrated here ispreferably made of steel. However, those having ordinary skill in theart will appreciate that the sleeve 26 may be made of any material thatis non-combustible and capable of retaining rigidity and integrity inthe event of a fire in the immediate surroundings of the sleeve 26.

[0046] It would, of course, also be possible to provide the fire collar10 with a sleeve 26 that is discontinuous and openable. In particular,it may be convenient or essential that the sleeve 26 be made in twosubstantially equal halves. Alternatively, the sleeve 26 may have afirst, smaller portion that is connected to a second, larger portion.

[0047] In the preferred embodiment, the fire collar 10 is generallycylindrical, like the pipe 12 around which it is fitted. Of course, ifit is desired to protect a partition having a pipe or other structuredisposed therethrough that has a cross-section that is other thancircular, the fire collar 10 may have a correspondingly non-circularcross-section.

[0048] Installation of the fire collar 10 is easier, lesstime-consuming, and, therefore, less expensive than installation of thefire collars presently known in the related art. Further, installationof the fire collar 10 requires fewer parts than installation of the firecollars of the related art requires. Also, the fire collar 10 preventsthe creation of noise when a plastic pipe expands and contracts within ahole of a wooden partition. And, the fire collar 10 may be installed atthe time the building is plumbed. In this way, the contractor who isinstalling the piping and securing the fire collar 10 is not required toreturn to the piping site to secure the fire collar 10 afterinstallation has been completed.

[0049] The present invention has been described in an illustrativemanner. It is to be understood that the terminology that has been usedis intended to be in the nature of words of description rather than oflimitation. Many modifications and variations of the present inventionare possible in light of the above teachings. Therefore, within thescope of the appended claims, the invention may be practiced other thanas specifically described.

What is claimed is:
 1. A fire collar that is adapted to inhibit flame propagation through a partition and be supported around a pipe extending through a hole in the partition, said fire collar comprising: a non-combustible, elongated sleeve having a pair of opposed, open ends; and a layer of expandable material carried on the inner circumferential surface of said sleeve, said layer being adapted to be constrained by said sleeve to expand in volume radially inwardly toward the pipe to collapse the pipe in the event the temperature of the material is raised above a predetermined level, said layer and the collapsed pipe together forming a physical barrier across said sleeve to block the hole; and a removable, elastic, interference member adapted to be disposed about the outer circumference of the pipe and between the inner circumferential surface of said sleeve and the pipe to create an interference fit therebetween to retain said sleeve relative to the pipe.
 2. A fire collar as recited in claim 1, wherein said sleeve has an annular bead disposed completely about and projecting outwardly from the general outer periphery of said sleeve such that the sides of said bead are disposed at a predetermined angle with respect to said sleeve.
 3. A fire collar as recited in claim 2, wherein said bead is disposed approximately one-quarter inch deep and one inch wide.
 4. A fire collar as recited in claim 2, wherein the predetermined angle approximates 45°.
 5. A fire collar as recited in claim 2, wherein said bead is located longitudinally offset with respect to the axial length of said sleeve and closer to one end of said sleeve.
 6. A fire collar as recited in claim 5, wherein said bead is disposed proximate the lower end of said sleeve and distal the upper end of said sleeve.
 7. A fire collar as recited in claim 6, wherein said bead is disposed approximately three-quarters of an inch from the lower end of said sleeve.
 8. A fire collar as recited in claim 2, wherein said bead defines a space that is designed to be filled with said layer of expandable material.
 9. A fire collar as recited in claim 2, wherein said layer of expandable material may be a composition strip one-quarter inch thick and one inch wide that is held in place to the inner circumference of said bead.
 10. A fire collar as recited in claim 1, wherein said sleeve is of a substantially right-cylindrical shape.
 11. A fire collar as recited in claim 1, wherein said sleeve is made of steel.
 12. A fire collar as recited in claim 1, wherein said sleeve has a thickness sufficient to protect the pipe from damage from exterior said sleeve.
 13. A fire collar as recited in claim 1, wherein said sleeve has a sufficient length such that the upper portion of said sleeve serves as a nail plate providing protection to the pipe through the partition.
 14. A fire collar as recited in claim 1, wherein said interference member may be a member of a group consisting of a washer, an O-ring, and a rubber band.
 15. A fire collar that is adapted to inhibit flame propagation through a partition and be supported around a pipe extending through a hole in the partition, said fire collar comprising: a non-combustible, elongated, substantially right-cylindrical sleeve having a pair of opposed, open ends, said sleeve having a thickness sufficient to protect the pipe from damage from exterior said sleeve and having a sufficient length such that the upper portion of said sleeve serves as a nail plate providing protection to the pipe through the partition; an annular bead disposed completely about and projecting outwardly from the general outer periphery of said sleeve such that the sides of said bead are disposed at a predetermined angle with respect to said sleeve and define a space therebetween, said bead disposed longitudinally offset with respect to the axial length of said sleeve and closer to one end of said sleeve; a layer of expandable material carried in said space, said layer being adapted to be constrained by said sleeve to expand in volume radially inwardly toward the pipe to collapse the pipe in the event the temperature of the material is raised above a predetermined level, said layer and the collapsed pipe together forming a physical barrier across said sleeve to block the hole; and a removable, elastic, interference member adapted to be disposed about the outer circumference of the pipe and between the inner circumferential surface of said sleeve and the pipe to create an interference fit therebetween to retain said sleeve relative to the pipe.
 16. A fire collar as recited in claim 15, wherein said bead is disposed approximately one-quarter inch deep and one inch wide.
 17. A fire collar as recited in claim 15, wherein the predetermined angle approximates 45°.
 18. A fire collar as recited in claim 15, wherein said bead is disposed proximate the lower end of said sleeve and distal the upper end of said sleeve.
 19. A fire collar as recited in claim 18, wherein said bead is disposed approximately three-quarters of an inch from the lower end of said sleeve.
 20. A fire collar as recited in claim 15, wherein said layer of expandable material may be a composition strip one-quarter inch thick and one inch wide that is cemented in place within said space. 